Fix call graph analysis

CHANGES.md

@@ -1,7 +1,9 @@
 #dev
 
 ## Features/Changes
-* Compiler/wasm: omit code pointer from closures when not used (#2059)
+* Compiler/wasm: omit code pointer from closures when not used (#2059, #2093)
+
+## Bug fixes
 * Compiler: fix purity of comparison functions (again) (#2092)
 
 # 6.2.0 (2025-07-30) - Lille

compiler/lib-wasm/call_graph_analysis.ml

@@ -15,11 +15,11 @@ let block_deps ~info ~non_escaping ~ambiguous ~blocks pc =
   let block = Addr.Map.find pc blocks in
   List.iter block.body ~f:(fun i ->
       match i with
-      | Let (_, Apply { f; _ }) -> (
+      | Let (_, Apply { f; exact; _ }) -> (
           match get_approx info f with
           | Top -> ()
           | Values { known; others } ->
-              if others || Var.Set.cardinal known > 1
+              if (not exact) || others || Var.Set.cardinal known > 1
               then Var.Set.iter (fun x -> Var.Hashtbl.replace ambiguous x ()) known;
               if debug ()
               then

compiler/tests-wasm_of_ocaml/dune

@@ -5,3 +5,12 @@
   (flags :standard --disable optcall --no-inline))
  (wasm_of_ocaml
   (flags :standard --disable optcall --no-inline)))
+
+(tests
+ (names gh2093)
+ (modes wasm)
+ (enabled_if
+  (>= %{ocaml_version} 5))
+ (wasm_of_ocaml
+  (compilation_mode whole_program)
+  (flags :standard)))

compiler/tests-wasm_of_ocaml/gh2093.expected

@@ -0,0 +1,11 @@
+IN
+peform E
+OUT
+handled E
+IN
+peform E
+OUT
+handled E
+IN
+done
+OUT

compiler/tests-wasm_of_ocaml/gh2093.ml

@@ -0,0 +1,70 @@
+(*
+Copyright (c) 2015, KC Sivaramakrishnan <[email protected]>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*)
+
+(* User-land dynamic wind:
+   http://okmij.org/ftp/continuations/implementations.html#dynamic-wind *)
+open Effect
+open Effect.Deep
+
+let dynamic_wind before_thunk thunk after_thunk =
+  before_thunk ();
+  let res =
+    match_with
+      thunk
+      ()
+      { retc = Fun.id
+      ; exnc =
+          (fun e ->
+            after_thunk ();
+            raise e)
+      ; effc =
+          (fun (type a) (e : a Effect.t) ->
+            Some
+              (fun (k : (a, _) continuation) ->
+                after_thunk ();
+                let res' = perform e in
+                before_thunk ();
+                continue k res'))
+      }
+  in
+  after_thunk ();
+  res
+
+type _ Effect.t += E : unit Effect.t
+
+let () =
+  let bt () = Printf.printf "IN\n" in
+  let at () = Printf.printf "OUT\n" in
+  let foo () =
+    Printf.printf "peform E\n";
+    perform E;
+    Printf.printf "peform E\n";
+    perform E;
+    Printf.printf "done\n"
+  in
+  try_with
+    (dynamic_wind bt foo)
+    at
+    { effc =
+        (fun (type a) (e : a Effect.t) ->
+          match e with
+          | E ->
+              Some
+                (fun (k : (a, _) continuation) ->
+                  Printf.printf "handled E\n";
+                  continue k ())
+          | _ -> None)
+    }